hello

Please clarify. Is this your phone that you marked as lost? Or is this a phone you found that is locked with someone else’s icloud account?

Only the owner of the account used to lock it can remove the activation lock.

That phone is useless to your. Return it for a refund if possible or recycle it and get a phone you can use.

Get your money back.

If you can't do that, turn it over to the police.